Modification of Dynamic Chambers to Reduce Variability.

Agriculture is a major source of ammonia emissions, accounting for nearly half of total ammonia emissions.   In order to better understand ammonia emissions in agriculture, a cost-effective, practical, and precise method to detect and analyze gaseous ammonia in a field setting is needed.  Dynamic chambers are a cost-effective method, but the results are often highly variable.  This study focuses on ways to improve the use of dynamic chambers.  Initial tests will be conducted on individual components in sealed chambers.  Ammonium chloride will be added to alkaline sand to ensure ammonia emission uniformity in the lab tests.   Six variables will be examined:  1) moisture content; 2) acid type; 3) filter paper size and number; 4) ammonia extractant; 5) air flow in chamber; and 6) filter placement in the chamber.   All treatments will be replicated four times.   The most promising treatments will be incorporated into modified dynamic chambers and tested.  The frame of the dynamic chambers will be inserted into large wooden boxes filled with alkaline sand representing a field setting.  Known quantities of ammonium chloride will be added to the sand in select locations.  Ammonia emissions will be measured comparing standard and modified dynamic chambers.  Costs of the study will be compared.  Results of the study will be presented.